From mboxrd@z Thu Jan 1 00:00:00 1970 From: nicolas.pitre@linaro.org (Nicolas Pitre) Date: Sun, 24 Jul 2016 11:30:17 -0400 Subject: [PATCH v5 03/15] binfmt_flat: prevent kernel dammage from corrupted executable headers In-Reply-To: <1469374229-21585-1-git-send-email-nicolas.pitre@linaro.org> References: <1469374229-21585-1-git-send-email-nicolas.pitre@linaro.org> Message-ID: <1469374229-21585-4-git-send-email-nicolas.pitre@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Signed-off-by: Nicolas Pitre --- fs/binfmt_flat.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c index c3ccdefdea..03301bad1f 100644 --- a/fs/binfmt_flat.c +++ b/fs/binfmt_flat.c @@ -466,6 +466,17 @@ static int load_flat_file(struct linux_binprm *bprm, } /* + * Make sure the header params are sane. + * 28 bits (256 MB) is way more than reasonable in this case. + * If some top bits are set we have probable binary corruption. + */ + if ((text_len | data_len | bss_len | stack_len | full_data) >> 28) { + pr_err("bad header\n"); + ret = -ENOEXEC; + goto err; + } + + /* * fix up the flags for the older format, there were all kinds * of endian hacks, this only works for the simple cases */ -- 2.7.4